The sensor test box allows the operator to make "Good" or "faulty" decisions with ease. Although it is not accurate, it also enables an assessment of the calibration. A push switch allows to test if the battery has deteriorated too far and needs replacement before sensible results are obtained.

The short circuit LED will indicate when the current of the connected sensor exceeds 7.5 milli Amp. The "Signal" LED lights with every pulse from the sensor. This can be used when the pulsing rate is very slow. i.e. Raingauge or windspeed. The "Period" light equals the input pulse divided by 128.

This indicator can be used for sensors with a fast output pulse rate. For instance: if the input frequency is supposed to be 40 pulses/second the LED should flash once every (128/40)=3 seconds